The West Cache fault zone (WCFZ) extends about 56 kilometers along the west side of Cache Valley in northern Utah, and another 37 kilometers into southern Idaho. This project mapped about 910 square kilometers in northern Utah, including the WCFZ and three other nearby Quaternary faults. Mapping was compiled at a scale of 1:24,000 and is published at a scale of 1:50,000. The goal of this study, as for other mapping studies along the WFZ, is to provide basic geologic data needed for accurate assessments of paleoseismic history and earthquake hazards associated with Quaternary faults.